A sputum fungal smear is a laboratory test that looks for fungus in a sputum sample.
Sputum is the material that comes up from air passages when you cough very deeply.

Alternative Names:

KOH test; Fungal smear - sputum

How the test is performed:

A sputum sample is needed. You will be asked to cough deeply and spit any material that comes up from your lung into a special container.

The sample is sent to a lab. A small amount is lightly smeared onto a microscope slide and mixed with potassium hydroxide (KOH). The slide is examined under the microscope and checked for fungus parts.

How to prepare for the test:

There is no special preparation.

How the test will feel:

There is no discomfort.

Why the test is performed:

Your doctor may order this test if you have abnormal sputum production or signs of a lung infection.

Normal Values:

A normal test should show no fungus on the microscope slide.

Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

What abnormal results mean:

Abnormal results may be a sign of a fungal infection. Such infections include: